In telecommunication systems, protection devices are employed to protect equipment from the effects of lightning or other high voltage surges and unwanted voltages of lower magnitude. A protector device is placed in a connection between a telephone exchange line of the local telecommunication provider and telecommunication equipment often at a customer location. The protection device protects the equipment connected to the exchange line from extraneous power sources and surges.
The protection device includes an input transmit and receive connection with the exchange facility and an output transmit and receive connection with the protected equipment. The protection device includes a mechanism for automatically disconnecting one or both of the input or output connections in the presence of a prolonged over voltage surge. The protective mechanism includes a voltage suppressor operatively coupled to the transmit and receive connections to the incoming line. Also included is one or more normally closed fusible links which are sensitive to voltage surges. The fusible links become open when an excessive current or voltage is applied to the fusible link thereby providing a protective function. Typically, each fusible link has a predetermined voltage rating or threshold. Additionally, often protection devices include a voltage suppressor, transformer, and a relay that may be connected between the transmit and receive connections within the protection device to protect connected telecommunication equipment from power and surge transients.
Semiconductor based components of telecommunication equipment are susceptible to excessive voltage including transient over voltages that last only a few microseconds. Transient Voltage Surge Suppression (TVSS) protection devices, which are often referred to as surge suppressors and voltage-clamping devices, are commonly used in suppressing such over voltage transients to protect voltage-surge intolerant telecommunication equipment.
In operation, one or more of the fusible links in the protection device becomes open when the incoming transmit and/or receives experiences a voltage or current surge greater than a predetermined amount. When a fusible link becomes open, the connection path between the input telecommunication transmit and/or receives becomes open and the signal is not provided to the output transmit and/or receive terminals of the protection device. As such, the communication path becomes disconnected and the communication provided by the communication facility is interrupted. In such a case, the telecommunication equipment and/or the communication user may determine that the communication has ceased to operate, however, neither the user or the telecommunication service provider can identify the source of the outage as being an open circuit or fuse within the protection device.
In some cases, protection devices may include a visual indicator such as an LED, flag, or pin. However, in order to identify the source of the outage being the open fusible link, a person must attend to the protection device and visually observe the visual indicator.
As such, the inventors have identified a need for a protection device for a telecommunication facility wherein the status of an open condition of a fusible link within the protection device may be identified from a location remote from the protection device. Furthermore, the inventors have identified the need for remote monitoring of the protection device in order to provide an alarm or indicator signal to a remote location when a fusible link of the protection device becomes open.
Generally surge suppression devices shunt damaging electrical energy to earth ground to protect attached equipment from damage from energy surges on the serving communication facility. Typically, these surge suppression devices can protect against energy surges that are less than or equal to a maximum energy level. When an energy level greater than the maximum level occurs, surge suppression devices commonly sacrifice themselves to provide for protection of the equipment. When the surge suppression device sacrifices itself, the device generally disconnects the incoming line from the equipment line which results in a disruption of the communication circuit and service provided by the communication facility. The disconnection results either from an opening of the normally closed circuit such as when a fuse blows or by a shorting of the circuit to ground which draws the communication signal to ground.
Generally, the service provider and the communication user are not provided with an indication of the failure of the surge suppression device except as may be indicated by a disruption of the communication service or an alarm notification associated with such carried service. In some cases surge suppression devices have been equipped with a visual indicator on the surge suppression device itself such as a light or light emitting diode. However, visual indicators require a person such as a technician visually inspect the visual indicators which helps in repair and maintenance of the facility, but does not help in remotely identifying the source and location of the problem.
Visual indicators in protective devices are configured to be powered by a portion of the energy of the communication signal to provide an indication of when the suppression circuit is working or has failed. However, the communication signal is sensitive to energy drains and may in fact cease working due solely to the energy requirements of the visual indicator. As such, visual indicators are not typically provided in protective devices.
Recognizing these and other problems and limitations of other systems, the inventors of the present invention have developed a surge suppressor system and method for data communication lines that provides, among other benefits, an indication of an event such as a failure of a surge suppression capability of the surge suppressor without requiring energy from the communication facility or service. The event indication may provide for a local visual indication and/or a remote indication signal when a surge suppression circuit sacrifices in response to a protection of the equipment from an energy surge on the incoming facility.